Heater for bitumen or other materials



pt! v J, T. M. JOHNSTON HEATER FOR BITUMEN OR OTHER MATERIALS Filed Sept. 26, 1922 2 Sheets-Sheet 1 mvm'row:

' 2 fi w m Q MJVLD W Sept. 18,1923. 1,468,365

J. T. M. JOHNSTON HEATER FOR BITUMEfi OR OTHER MATERIALS Filed sept. 26, 1922 2 Sheets-Sheet 2 I F t/30% WW 35 Him M...

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Patented Sept. 18, 1923.

JAMES rnonms ITCHELL .ionns'ron, or Lennon, ENGLAND.

HEATER FOR BITUMEN OR OTHER MATERIALS.

Application filed September 26, 1922. Serial No. 590,718. 1

To 'all whom it may concern. 1

Be it known that I, JAMES THOMAS MITCHELL JOHNSTON, a subject of the King of England, residing at London, England, have invented certain new and useful Improvements in Heaters for Bitumen or Other Materials, of which the following. is

a specification;

Difficulty is experienced in melting mate rials such as bitumen or pitch'owing partly to their low heat conductivity and partly to their relatively high latent heat of fusion,

much time and labour being occupied in melting such materials in -cauldrons or boilers, such as are used in road-making, since the mixture of solid and liquid materials has to be stirred continually for some considerable time before the whole mass is melted.

The present invention, while applicable to the melting of solid or semi-solid materials generally, is particularly applicable to apparatus used for melting and heating bitumen, pitch or similar solid materials used in road-making or similar operations, and in this connection'the object of the invention is to provide such an apparatus which will melt solid bitumen or the like more quickly than those hitherto in use and without the laborious stirring which has here-V tofore been necessary.

Accordingly, the invention consists in a heater for bitumen or other material having a heated support for solid material which is provided with means, or is con structed, to prevent escape of, the solid matematerial to flow fromit. Thus heat is transmitted directly to the solid material; during the whole period 'of'meltin'g, since the liquid. material flows away fromthe support and cannot therefore obstruct the,

passage/of heat to the material to be melted.

The heated support is perferably combined with a cauldron to constitute a unitary device and the said support is so mounted in relation tothe cauldronthat the molten material flows into-the cauldronby gravity.

The said support maybe a grid of fluepipes, through which the furnace gases pass .(for example the gases from the furnace that heats'the receptacle for the molten material), this grid of flue-pipes being preferably arrangedsubstantially horizontally above the said receptacle-for example the a parallel with said cauldronof a portable bitumen melter and heater.

Preferably, the cauldron is heated by a flue or fines for furnacegases either from the same furnace as that which supplies the grid of flue-pipes, or from a separate furnace. -The flue or fines are preferably in gridland dampers are provided whereby the flow of furnace gases through the grid-pipes and the flue or lines may be separately controlled.

A heater for bitumen, pitch or the like for use in road-making or similar operations,

and constructed according to this invention is illustrated in the accompanying draw ings, in Which Figure l is 'a' side tion, and

Figure 2 is a section on Figure 1. p

Both figures of the drawing are to some extent diagrammatic, in order to show the construction more clearly. 7 V

A frame 1, mounted on wheels 6, supports a "double-wall cauldron consisting of a cauldron proper Sand an outer casing 10, there elevation partly in secthe line 2-2 in being a space between the cauldron and the casing extending round the four sides of the cauldron and beneath it, as clearly shown in both figures of the drawing.

A furnace 12 communicating with the space between the cauldron and the casing is arranged below the frame. The products of combustion from this furnace pass through the-space aforesaid and into an uptake 14. rial upon it while permitting the melted A second furnace 16 beneath the frame communicates with a chamber 18 which extends upwardly within the cauldron 8. This chamber 18 does not extend completely across the cauldron except at its top, and is spaced from the forward end of the cauldron, so that the latter extends round three sides of the lower part of the chamber and a 24 trend; slightly; upwards towards the ill;

smoke-box, from which extends an uptake 26. The two uptakes 14 and 26 open into a common chimney 28 which is hinged, as at 80, to enable itto be turned horizontally along the top of the cauldron. Each uptake is provided with a sliding damper (32- and 34 respectively) so that the draught of either orboth of the furnaces 12 and 16 may be controlled.

The cauldron is closed at the top by cen trally hinged lids 36 'provided with handles 37', there being three such lids on each side.

Inorder to preventburning of the bottom ofthe cauldron 8, a removable iron plate (not shown) is preferably secured to the bottom of the cauldron immediately above the furnace 12. r V

It will readily be'understood that the flue-pipes 22, the top ofithe chamber 18, and

the-plate 19 heated by. gases from the furnace16, togetherconstitute a grid-like melt ing' surface, and that solid bitumen, pitch or other material' placed uponit will be re tained thereupon and rapidly melted-, the liquid flowing into the cauldron below where it is kept hot by the heat of the two furnaces transmitted through the bottom and sides of the cauldron 8, the sides of the chamber 18-and the pipes 24.

In order to enable. the pipes 22 to. be closed independently of the pipes 24, a removable daniper-plate 384s provided in the chamber 18, resting on angle-irons 39 secured to theflwalls of the chamber, and it will beseen that by manipulating the dampersi32, Maud 38 any desired effect can be produced. ll hen starting to melt bitumen.

the damper 32 is closedand a damper 38 is removed, so that the pipes alone are heated. Then the cauldron is 7 full, the damper 38 is replaced; and if, at the end of a days use, the cauldron still has some bitumen. in it, both: dampers 34. and 38 are.

closed, and the furnace 12 banked up for the night, inorder to maintainthe bitumen in a liquid condition. If bitumen is allowed to solidify in-the cauldron,.it maybe melted "comparativelyquickly by closing the damper 38" and opening; both uptake dampers 82 and 341:.- V

' The melted material is drawn offthrough apipe 4O and'coclc 42, the pipe 4L0:passing 'throughthe smoke-box 20 and the space between the cauldron and the outer casing,

whereby chilling of the material and choking oii the pipe are prevented.

The size and spacing of-the pipes 22 as shownin thedrawings are suitable for ma-' terials which-are solidat ordinary tempera tures. In a heater according-t0 this invention intended for liquefying semi-solidmaterials such asa mixture of tar and pitch, the pipes constituting the grid are prefergether than those shown:

or preferably both rollers and wheelsmay be used, the-latter being of larger diameter than the former and mounted for easy removalfrom the axlesw-lii this case the ablv smaller and spaced more closely towheels are used for transporting'the boiler and'are removed so that the boiler restson the rollers when in use for road-making.

lVhen melting and heating what is known as filled bitumen-thatis, bitumen mixed with sand'or other fillerit is advisable to agitate the melted material in the cauldron, in order to prevent the filler from separating out. This may be done in the apparatus above described by providing rotary or other agitators or paddles within the cauldron, to

. be rotated eitherby hand orby power. The

lower tubes 24 may be omitted when agitators are provided. r I v The filler may of course be added to unfilled bitumen or other material in the cauldron. In this case it is preferable-to introduce the filler through tubes or oth'er-con duits opening below. the tubes 22, inorder to prevent fouling of the latter.

I 'claim: 1 r

1. In apparatus for melting. and heatingbitumen or llke material, the combination of a cauldron-for conta ning molten material,

a plurality of tubes constituting a grid' like 1 V melting device situated above-the levelof' the material in the cauldron, which device is adapted to retain solid or semisolid ma terial upon it and to-permit-melted material to flow through it into the cauldromafurnace for heating the cauldron, flues'in-said cauldron below'the normal level iof the, molten mZLlZGIRIhtllGIGIIQ a second furnace arranged to heat the cauldromand means for supplying furnace gases from said sec- 0ndfurnace through said fiuesiand the tubes of said melting device in; parallel,'-substan-: 'tiallyasdescribcdw it 1 forxmelting and heating 2.: In apparatus bitumen or lik-e inaterialy the combination ofa cauldron for containing-molten material, a plurality-oftubes constituting a gridlike melting device situated-above the' level of the material in the cauldron, which device I no is adapted to retainsolid or semi solid ma V terial upon it and to permit melted material 1 to flow through it into thecauldron; a fur- I nace for heatingthe cauldron, lines in said f cauldron below the 1 normal level" of the molten material thereinria seconclufurnace,

means for supplyingfurnace gases from said second furnace-through said-flues-and the tubes of said melting device in parallel, and means controllingindependentlythe passage 1 of the furnace gases'through saidflues and said tubes, substantially asdescribed; V

"3. Apparatus. for melting and heating. bitumen or other material, comprisingin' combination a cauldromafurnace-for heatr J only the upper part of which extension ex ing the same, a second furnace having a box-likeextension in one end of the cauld'ron, an lip-take for gasesatthe other end of thecauldron, a grid of heating tubes constituting a support for solid material to be melted situated in the upper part of the cauldron, smoke tubes situated in the lower part of said cauldron said heating tubes and smoke tubes opening into said box-like extension and into said up-take, and means for controlling independently the passage of furnace gases through said heating tubes and said smoke tubes, substantially as described.

4. Apparatus for melting and heating bitumen or other material, comprising in combination a cauldron, a furnace for heating the same, a second furnace having a boxlike extension in one end of the cauldron,

' tends from side to'side of the cauldron, an

'up-take for gases at the other end of the cauldron, a grid of heating tubes constituting a support for solid material to be melted situated in the upper part of the cauldron and opening into the upper part of said boxlike extension and said up-take, smoke tubes situated in the lower part of said cauldron.

and opening into the lower part of said boxlike extension and said up-take, and a damper for shutting off the said upper from the said lower part of said box-like extension, substantially as described.

5. 'Apparatus for melting and heating bitumen or other material, comprising in combination a cauldron, a furnace for heat- 7 ing the same, a chimney, a cauldron-heat1ng flue connecting said furnace with said chimney, a secondfurnace having a box-like extension in one end of the cauldron, only the upper part of which extension extends from side to side of the cauldron, an uptake for gases at the other end of the cauldron opening into said chimney, a grid of heating tubes constituting a support for solid material to be melted, situated in the upper part of the cauldron and opening into the upper part of said box-like extension and eating with said furnace, a grid of flue-pipes e constituting a support for solid material to be melted and situated in the upper part of the cauldron, a plurality of smoke-tubes situated in the lower part of the cauldron, a second furnace communicating with the grid of flue-pipes and with the smoke-tubes, and means forcontrolling independently the passage of furnace gases through the cauldron-heating flue, through the smoke tubes and through the rid of flue-pipes.

In testimony whereof I aflix my signature.

JAMES THOMAS MITCHELL JOHNSTON. 

